I have used NFC (Near Field Communication) tags embedded in my 3D prints for many different applications and I have some great ideas for future projects. The tags are cheap and survive the temperature of the printing process. The limitations are that of memory per tag and that of NFC adoption in phones... currently apple is not on board for open use.
I would love to hear feedback from Ingress Agents and your ideas for applications with the current game features... The idea of "cryo storage" of equipment in a physical object via NFC has been tossed around since beta.
Some applications I've played with: http://imgur.com/a/IUYzw#0
-A print of a scan of my friend as she recorded a Johnny Cash cover... the embedded tag is linked to the recording on her reverbnation profile.
-A turntable model with matching records for a DJ. Each record had a tag linked to different tracks from his site.
-Keychains linked to sites to promote a Radio Show, Real Estate Agent and Sports Therapy Professional
-A "ON AIR" table top sign for a radio show with an embedded tag programmed to change the phone state to silent mode.
-Lanyard flair linked to My Service Sites and Community Profiles
-I printed a model of a floppy disc with a tag embedded.... it is a data storage art piece of sorts.
I've added a gallery of 3D designed and printed Ingress stuff for reference. There are also new things added everyday on http://www.thingiverse.com/search/page:1?q=ingress&sa=
You can find your local 3D printer through www.makexyz.com
and they will soon all have this NFC feature available.